Common mental health disorders, such as depression, generalised anxiety disorder, panic disorder, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD) and social anxiety disorder, may affect up to 15% of the population at any one time. Depression and anxiety disorders can have a lifelong course of relapse and remission. There is considerable variation in the severity of common mental health disorders, but all can be associated with significant long-term disability. For example, depression is estimated to be the second greatest contributor to disability-adjusted life years throughout the developed world. It is also associated with high levels of morbidity and mortality, and is the most common disorder contributing to suicide.
The prevalence of individual common mental health disorders varies considerably. The 1-week prevalence rates from the Office of National Statistics 2007 national survey were 4.4% for generalised anxiety disorder, 3.0% for PTSD, 2.3% for depression, 1.4% for phobias, 1.1% for OCD, and 1.1% for panic disorder. Estimates of the proportion of people who are likely to experience specific disorders during their lifetime are from 4% to 10% for major depression, 2.5% to 5% for dysthymia, 5.7% for generalised anxiety disorder, 1.4% for panic disorder, 12.5% for specific phobias, 12.1% for social anxiety disorder, 1.6% for OCD and 6.8% for PTSD. More than half of people aged 16 to 64 years who meet the diagnostic criteria for at least one common mental health disorder experience comorbid anxiety and depressive disorders.
The vast majority (up to 90%) of depressive and anxiety disorders that are diagnosed are treated in primary care. However, many individuals do not seek treatment, and both anxiety and depression often go undiagnosed. Although under-recognition is generally more common in mild rather than severe cases, mild disorders are still a source of concern. Recognition of anxiety disorders by GPs is particularly poor, and only a small minority of people who experience anxiety disorders ever receive treatment. In part this may stem from GPs' difficulties in recognising the disorder, but it may also be caused by patients' worries about stigma, and avoidance on the part of individual patients.
The most common method of treatment for common mental health disorders in primary care is psychotropic medication. This is due to the limited availability of psychological interventions, despite the fact that these treatments are generally preferred by patients.
Since 2004, NICE has produced a series of guidelines on the care and treatment of common mental health disorders (see section 6 for details of related guidelines). Some of these guidelines focus on identification and recognition (for example, the guideline on depression), whereas others give little advice on identification (for example, the guideline on generalised anxiety disorder and panic disorder). In addition to the variable advice on identification and recognition, NICE guidelines have also varied in the amount of advice they have provided on assessment and appropriate referral for the treatment of these disorders.
The intention of this guideline, which is focused on primary care, is to improve access to services (including primary care services themselves), improve identification and recognition, and provide advice on the principles that need to be adopted to develop appropriate referral and local care pathways. It brings together advice from existing guidelines and combines it with new recommendations concerning access, assessment and local care pathways for common mental health disorders.
A number of the recommendations in this guideline were adapted from recommendations in other NICE guidelines for common mental health disorders. In doing so the Guideline Development Group were mindful that they had not reviewed the evidence for these recommendations and therefore when transferring them into this guideline were careful to preserve the meaning and intent of the original recommendation. Where recommendations were adapted, changes to wording or structure were made in order to fit the recommendation into this guideline; these adaptations preserved the meaning and intent of the recommendation but shifted the context in which the recommendation was made. In all cases the origin of any adapted recommendations is indicated in a footnote.
 NICE is developing the clinical guideline 'Social anxiety disorder: diagnosis and treatment' (publication expected 2013).
 McManus S, Meltzer H, Brugha T, et al (2007) Adult psychiatric morbidity in England, 2007: results of a household survey. Leeds: The Information Centre for Health and Social Care.